This invention relates to evaporative drying systems, hereinafter called dryers, more particularly to dryers that are used to dry-solvent based or water-based inks, paints or coatings.
Traditional dryers dry by projecting heated air and/or radiating heat energy. The most common form of a projected air dryer delivers lightly pressurized preheated air into a distribution plenum, which is then dispersed through a series of slots or circular orifices to the medium being dried. These types of dryers typically rely on large volumes of air to adequately dry, thus consuming substantial amounts of energy and requiring extensive air handling equipment.
In some of the more recent forced hot air dryers, compressed air is preheated prior to entering the distribution plenum(s). The preheating is typically accomplished by the use of a separate heat plant device such as the common triple pass or inline air heater. Using a heat plant that is separated from the air distribution system introduces inefficiencies of operation; additional equipment and manufacturing costs; and additional equipment. The added equipment can also make the dryer prohibitively large in size for some applications that have limited available space.
Current dryer systems have their operating controls located remotely from the distribution plenum(s), which increases the complexity of the controls system and the associated costs for the manufacturing and installation of the entire system.